Locking device for coupling semitrailers for draft vehicles



July 18, 1950 FOR DRAFT VEHICLES 5 Sheets-Sheet 1 Filed June 28, 1949 sm M a U S W 1 W 1 H H p A L I A R Y B 4 vllllL NU 'llll WINI P VWIWWFHHH TI L I I l I l 1 1| -\\N N\-\ O QGN Q NW NN wN Q wh,\\ nmw w mu N mww W n fl u HWvW MWIPI ll w. w w\ STARR LOCKING DEVICE FOR COUPLINGSEMITRAILERS July 18, 1950 R. w.

FOR DRAFT VEHICLES 5 Sheets-Sheet 2 Filed June 28, 1949 %w\ QN I m fimwmww wmwvmw -1 1 vy lx u 1 I I I I I I I I I I I I I I I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I III R T 9 3 R v imp/Iv?|||||m||||||11|III; IIIIIIIEIIIIII!m M 1 n7. 1 H PM b R BY WM S Y E N R o T T A July 18, 1950 R. w. STARR LOCKING DEVICEFOR COUPLING SEMITRAILERS FOR DRAFT VEHICLES 5 Sheets-Sheet 3 Filed June28, 1949 7 -H H I m v AM WE MI J IH: L I! I |MH| HH I H I l I I I I I II l MHHHHHHHNHHHHHHHMIM wm A 1 w m T uv V S W W M Q W MW MW W L g A *5 RQN wN WW MN l IN |I|I1N|M |[E. P l I I I I I I l l I .ll JQ \N N mx l|-I||| l| |||ll|+|l|ll| RN 4 l I I l l l I I I l I I I I I I I||+|||lll|||||'|Illllllllil'lllIllllllllll'llllllllllllllll paldfiyATTORNEY$ July 18, 1950 R. w. sTARR LOCKING DEVICE FOR COUPLINGSEMITRAILERS FOR DRAFT VEHICLES Fi led June 28, 1949 5 Sheets-Sheet 4INVENTOR.

RALPH W. STARR BY M S Y E N R o T T A July 18, 1950 R. w. STARR LOCKINGDEVICE FOR COUPLING SEMITRAILERS FOR DRAFT VEHICLES 5 Sheets-Sheet 5Filed June 28, 1949 R wN R QM w S Y wfi MRMM w mmflua mwk. w w w I T A NW I M WNW NW MW my Q Patented July 18, 1950 OFFICE LOCKING DEVICE FORCOUPLING SEMI- TB-AILERS FOR DRAFT VEHICLES Ralph Wayne Starr, YubaCity, Calif.

Application June 28, 1949, Serial No. 101,888

8 Claims. 1

The present invention relates to improvements in a locking device forcoupling a semitrailer to a draft vehicle. It consists of thecombinations, and arrangement of parts, as hereinafter described andclaimed.

This invention embodies improvements over the apparatus shown in myUnited States Letters Patent No. 2,434,443, granted January 13, 1948,entitled Full Automatic Landing Legs for Semi- Trailers.

In the above mentioned patent, I disclose retractable legs adapted tosupport the forward end of a semi-trailer when. a draft vehicle isdisconnected from the semi-trailer. These legs are retracted when thesemi-trailer is coupled to the draft vehicle. This invention hasparticular reference to the locking device for detachably retaining thesemi-trailer coupled to the draft vehicle.

An object of this invention is to provide a locking device forpositively holding the semi-trailer coupled to a draft vehicle, which isadapted to be manually released by the driver. During the initialuncoupling of the semi-trailer from the draft vehicle, the lockingdevice will reset itself for automatically interlocking the semi-trailerand the draft vehicle when they are coupled together again.

Moreover, I propose to provide a device of the character described thatis simple in construction, durable and efficient for the purposeintended, and positive in action.

Other objects and advantages will appear as the specification continues.The novel features will be set forth in the claims hereunto appended.

For a better understanding of the invention,

reference should be had to the accompanying drawings, forming part ofthe application, in which:

' Figure 1 is a plan view of the forward portion of the chassis of asemi-trailer, disclosing the king-pin of a draft vehicle fully coupledto the semi-trailer and secured thereto by my locking device;

Figure 2 is a similar view, but showing the locking device moved topermit withdrawal of the king-pin when the draft vehicle is movedforward from the semi-trailer;

Figure 3 is a view similar to Figure 2, and illustrates the king-pinbeing pulled forward and the clam jaws on the semi-trailer resetting thelocking device;

Figure 4 discloses the next step in which the king-pin of the draftvehicle is fully disconnected from the semi-trailer;

Figure 5 is a transverse vertical sectional view taken along the lineV-V of Figure 3;

Figure 6 is a side elevation of the forward part of the semi-trailersupported by the retractable legs, the draft vehicle and its king-pinbeing shown in dot-dash lines; and

Figure 7 is a transverse sectional view taken along the line VII-V11 ofFigure 6. While I have shown only the preferred form of my invention, itshould be understood that various changes, or modifications, may be madewithin the scope of the annexed claims without departing from the spiritthereof.

Detailed description Referring to the drawings, and particularly toFigure 6 thereof, the semi-trailer is designated generally at A. Thissemi-trailer includes spaced-apart chassis frames ID, the rear portionsof which are supported by wheels (not shown) in the conventional manner,well understood in the art. The forward portions of these frames areadapted to be supported by a draft vehicle B when the semi-trailer iscoupled thereto for towing purposes. However, when the draft vehicle isdetached, the forward portion of the semitrailer is supported byretractable legs C. The latter are retracted automatically above theroadway [I when the semi-trailer is fully coupled to the draft vehicle.

The draft vehicle B carries a lower fifth wheel 12 having a king-pin l4rising therefrom. An

upper fifth wheel 15, in the nature of a plate, is secured to theunderneath sides of the forward portions of the chassis frames [0. Whenthe draft vehicle is backed under the forward end of the semi-trailer,as suggested in Figure 6, the lower and upper fifth wheels slide overone an other in the usual manner. 1

The semi-trailer is provided with coupling and locking devices D and D,respectively, for detachably engaging with the king-pin M of the draftvehicle for coupling the semi-trailer to the draft vehicle. In general,the coupling device includes a clam lock composed of a pair ofswingably-mounted coacting jaws I6, which are oper-' able by areciprocable movement. These jaws slide upon the plate l5, and when theyare re tracted (moved to the right in Figure 4), they enter a guidemember I1. The latter is in the nature of an inverted channel having itsflanges I8 welded or otherwise secured to the plate 15. It will be notedthat the plate I5 is fashioned with a slot l9 therein extendinglengthwise rela tive to the semi-trailer and along the centerline of thelatter. This slot is dimensioned to receive the king-pin Ill when thedraft vehicle is aligned with and backed with respect to thesemi-trailer; The forward end of this slot is flared outwardly, as atl9a, to facilitate introduction of the kingpin into the slot. Also,forwardly-diverging upright plates 20 are fixed to the plate I5 andmerge into the flanges it! of the guide member. l r The angularity ofthe plates 20 provide a throat into which the jaws it may expand uponpulling them forwardly, thus releasing their grip on the king-pin 14.However, upon retracting the jaws into the guide member ll, due tobacking the king-pin into the slot [.9 the jaws are moved together bythe inclined plates 20 so as to grip the king-pin therebetween. As theking-pin continues to move rearwardly, the jaws move alon the guidemember until they reach the position shown in Figure 1. At this time,the semitrailer is fully coupled and locked to the draft vehicle.

In Figure 4, I show the jaws l6 swung into open position and ready toreceive the king-pin l4 in the confronting recesses 16a of the jaws. Ahook-shaped member or locking dog 2| is pivoted to one of the jaws, asat 22. When the jaws are fully opened, the lever-like end 2 In of themem ber 2| is disposed in an opening 23 formed in one of the flanges l8and bears against a stop 24' provided n the latter (see Figure 4). Atension spring 22" working between the right-hand jaw l6 and the lockingdog 2| holds the jaws open in Figure 4, it being noted that anintermediate portion of the lever end 2 labears against a bolt 25disposed between the two jaws.

The lockin dog holds the jawsin their forward of the member or dog 2i,and the lever end Zia is swung in a counter-clockwise direction inFigure 4 so to clear the stop 24. The jaws are relatively heavy, ascompared with the dog 2!. The lighter weight dog is unlatched before theheavy jaws are pushed rearwardly. The bill 21b is dis- I posedsubstantially. along the center line of the guide member [1, whereas thebolt 25 is disposed to one side. This will facilitate unlatching of thedog. At this time, the jaws are moved into the guide member l1- and areclamped upon the interposed king-pin.

The jaws I6, are hinged by a bolt 25 to the forward end of a reach-bar26. A link 2|" is swingably mounted on the bolts. 22 and 25 and aids insupporting the locking dog. The reachbar mounted for reciprocablemovement along the centerline of the semi-trailer, and has. its forwardend. projecting into the guide member 11. The rear end of this reach-barhas a leg-operating travelling cam E fixed. thereto so. as. toreciprocate therewith,

In order to support the travelling cam E for reciprocation, I secure arail. 2l' thereto, and the latter is guided between a pair of rollers28. These. rollers are rotatablymounted in brackets 29-fixed to anddepending from an, angle iron 30 or the like. This angle iron extendstransversely of: the semi-trailer and is secured to. the chassis frames10, as clearly disclosed in Figures 6 and 7.

When the jaws t6 occupy their forward position, as in. Figures 4 and 6and are fully opened, the travelling cam E will be disposed at itsforward position as. in Figure 6. It is obvious that as the reach-bar 26is pushed rearwardly, due to the king-pin I4. moving the jaws. [6 towardthe rear, the cam E will be moved in the same direction.

This rear movement of the travelling cam E is utilized for elevating theretractable legs C above the roadway II when the forward end of thesemi-trailer A is supported on the draft vehicle B. On the other hand,forward movement of the cam E is utilized for extending the legs C intocontact with the roadway H, at which time they constitute support forthe forward end of the semi-trailer.

It will be understood that the legs C are duplicated on opposite sidesof the chassis frames Ill, and are swingably attached thereto at theirupper ends by a transverse shaft 3| and bearing journals 32. The lowerends of these legs carry yokes 33 on which ground-engaging wheels 34 arerotatably supported. The legs are interconnected by a transverse brace35 (see Figure 6). This brace has a pair of arms 36 fixed thereto, whichstraddle the travelling cam E. The latter has an arcuate guideway 31fashioned therein, which receives rollers 38 carried by the arms 36.

It will be apparent from Figure 6 that upon moving the travelling cam Erearwardly, the retractable legs C will swing counter-clockwise due tothe arcuate guideways 3 1 acting upon therollers 38; Accordingly, thewheels 34 will be lifted clear of the roadway H. The rearward movementof the travelling cam E'to elevate-the legs C results from thereach-bar- 26 and its jaws It being forced rearwardlyby the king-pin-[4.

For the purpose, of imparting: additional rigidity to the supportinglegs 0 when they are extended, I provide radius rods 39. These reds arehinged to the legs at 40' and slide in swingablymounted guides 4|, whichare arranged onthe chassis frames of thesemi-trailer- (see Figure 6)-.

Referring now to the details of my" locking device D', it will be seenthat I provide transverse guide members 42 and 43*, which are arrangedat right angles to the longitudinal guide member IT and on oppositesides thereof. Locking detents 44' and 45 are slidably disposed in theguide members 42 and 43-, respectively. These detents are adapted to beprojectedthrough openings [8a fashioned in the flanges H of thelongitudinal guide member fl'. Rods 48 have their inner ends secured tothese detents and their outer ends extend through, bearing openings 4'!provided in end walls 48 of' the transverse guide members 42 and 43.

The detents 44 and 45 are yieldingly urged toward one another by;springs 49, which encircle the rods 46'. When the jaws it are retractedrearwardly in the guide member IT to th position shown in Figure 1, thedetents are projected inwardly in front of the jaws I6; thus locking thejaws against being pulled forward relative to the guide member I]? untilsuch time as the detentsare retracted again. Accordingly, Figure 1illustrates the parts of the coupling and locking devices D and D,respectively, in the positions that v they occupy when the king-pin I4is being utilized for towing the semi-trailer A forward with the draftvehicle 3'.

In order to retract the detents 44 and 45, andthus allow the draftvehicle to be detached, I make use f a manually-swingable cam platev 50.The latter is mounted for movement about a pivot bolt 5;! which isanchored to theweb ofthe channel-shaped' guide member H (see Figure 5);.For the purpose of rocking this cam plate; I provide a lever 52, whichis fixed: to the plate 59; Apull rod 53 is connected, to the free end ofthey lever 52 and extends forwardly therefrom, terminating in a handle54 that is accessible to the driver or other person. (See Figure 6-.)

Referring to Figure 1 in particular, itwill be noted thatcam slots 54are provided in the swingable plate These slots are inclined withrespect to true arcs 55 of a circle described about the bolt 5i. Studs58' and 51- pass downwardly through the slots 54- and have their lowerends anchored to the locking detents 44-45, respec tively (see Figure5)-.

As previously stated, Figure l illustrates the locking detents 44--45disposed in front of the retracted jaws IE. Upon pulling the rod 53forwardly, the lever 52 will swing the cam plate 50 in a clockwisedirection. It is apparent that during such swinging of the cam plate theslots 54 and the studs 56-51 will cooperateto retract the lockingdetents 44-45, respectively, relative to the longitudinal guide memberI1. At this time, the parts of the locking device D will cupy thepositions shown in Figure 2.

The cam slot 54 through which the stud 51 projects is provided at oneend with a notch 54a, which is arranged to receive the stud 51 when theplate 50 occupies the positions shown in Figure 2. Particular attentionis called to the fact that the inner end 44a of the detent 44 has beenretracted so as to clear the upper jaw I6 in Figure 2, but thedouble-tapered inner end 4511 of the detent 65 still projects in frontof the other law I6.

Now the driver commences to move the draft vehicle 13 forward, and theking-pin I4 will operate to advance the jaws It toward the front end ofthe semi-trailer. This motion, of course, will pull on the reach bar 26and the travelling cam E will move the retractable legs C until thewheels 34 come into contact with the roadway I I.

During the initial forward movement of the jaws I6 relative to thelongitudinal guide member I1, the lower jaw It in Figure 3 will camitself over the inclined ends 45a of the detent 45. This will causefurther retraction of the detent 45 in-the transverse guide member 43until the stud 51 backs out of the notch 54a. Inasmuch as the detent 45is under spring tension, the stud 51 will cooperate with the inclinedslot 54 through which the stud 51 extends, causing the cam plate 5t toswing in a counter-clockwise direction until the plate 58 occupies theposition shown in Figure 3. This has resulted in resetting the lockingdevice D for snapping the detents in front of the jaws I6 when thelatter are subsequently withdrawn to the rear of the detents, as inFigure 1.

In Figure 4, I have disclosed the jaws I6 as being advanced to a pointnear the forward end of the semi-trailer. As the jaws enter theoutwardly flared throat between the forwardly-diverging plates Zil, thejaws will move apart, freeing the king-pin I4. Of course, the wheels 34of the retractable legs C have moved into contact with the roadway II bythis time and will support the forward end of the semi-trailer.

The back faces [6b of the jaws l6 converge rearwardly and curve aroundthe bolt 25. Thus when the jaws are forced along the guide member I1toward the back of the semi-trailer A, due to backing of the draft Brelative thereto, the jaws will earn themselves between the detents ik-45, urging the latter outwardly to permit passage of the jaws into thefully-coupled position shown in Figure 1.

Summary of operation Having thus described the various parts of mydevice, the operation thereof is summarized briefly as follows:

Assuming that the forward end of the semitrailer A is supported by theretractable legs C, as in Figure 6, and that the draft vehicle B isaligned with and is being backed relative to the semi-trailer, theking-pin will enter the slot I9 in the upper fifth wheel plate I5. Atthis time, the jaws I6 are fully opened, as shown in Figure 4, and aredisposed in the throat between the forwardly-diverging plates '20. Also,the leverlike end 2Ia of the hook-shaped member 2I will project throughthe opening 23 and rest against the stop 24.

As the king-pin continues to move rearwardly along the slot I9, it willstrike the bill-like end 2 lb of the member 2 I, swinging the lever end2 I a clear of the stop 24. Continued rearward movement of the king-pinand the angularity of the plates 2t will cause the jaws to move towardone another and clamp themselves upon the interposed king-pin as theyenter the guide member I1. These jaws will pass between the inner endsMae-45a of the detents 44-45, urging the latter outwardly, if necessary,to permit passage of the jaws to the rear of the detents.

This rearward movement of the jaws I6 has moved the reach-bar 26 towardthe back end of the semi-trailer, operating the travelling cam E to foldthe retractable legs C above the roadway I I. Thereupon, the detentswill snaptoward one another in front of the jaws IS. The parts of thecoupling and locking devices D and D, respectively, now occupy theposition shown in Figure 1. The semi-trailer A is fully coupled to thedraft vehicle B and may be towed away.

When the driver desires to uncouple the semitrailer A, the handle 54 ispulled forward. This will swing the cam plate 50 into the position shownin Figure 2, with the stud 51 entering the notch 54a to restrain the camplate 59 from swinging back into the position shown in Figure 1. Thishas freed the jaws so that they may be pulled forward by withdrawing thedraft vehicle and thus advancing the king-pin I4 along the slot I9.

The lower jaw I6 in Figure 2 will contact the rearmost sloping end 45aof the detent d5, forcing the latter outwardly to free the stud 51 fromthe notch 450., as clearly disclosed in Figure 3, thus resetting thelocking device D. Further advancement of the jaws I6 will move them intothe throat between the plates 25. This will permit the jaws to swingoutwardly about their pivot bolt 25 until the king pin I4 is freed fromthe jaws, as in Figure 4. The lever-like end 2Ia of the hook-shapedmember 2i has reentered the opening 23 to lock the jaws open and retainthe legs C extended, the wheels 34 having been lowered into contact withthe roadway If during the meantime. This completes the uncoupling of thesemi-trailer from the draft vehicle.

I claim:

1. In combination: a guide member extending longitudinally of asemi-trailer; a pair of cooperating king-pimgrasping jaws slidable alongthe guide member; a pair of locking detents disposed on opposite sidesof the guide member and having inner ends movable into the interior ofthe guide member to arrest forward movement of the jaws after the latterhave been moved into a position rearwardly of the detents; yieldingmeans urging the detents inwardly of the guide member; aswingably-mounted plate; and means connected to the plate to retract thedetents relative to each other when the plate is swung in one direction,and to advance the detents toward each other when the plate is swung inthe opposite direction; at least one of the detents have a tapered innerend engageable with one of the jaws for retracting that detent furtherfrom in front of said jaw after said detent has been partiallywithdrawn.

2*. In combination: a guide member extending longitudinally of asemi-trailer; a pair of operating' king-pi-n-grasping jaws slidable'along the guide member; a pair of locking detents disposed on oppositesides of the guide member and having inner ends movable into theinterior of the guide member to arrest forward movement of the jawsafter the latter have been moved into a position rearwardly of thedetents; yieldingrneans urging the detents inwardly of the guide member;a swingably mounted cam plate having slots therein inclined relative totrue arcs of a circle described about the pivotal point of the plate;studs secured to the detents and extending into the slots 01- the camplate; the slots being inclined and cooperating with the studs to movethe detents apart when the cam plate is swung in onedirection againstthe action of said yielding means.

31 In combination: a guide member extending longitudinally of asemi-trailer; a pair of (:0- operating king-pin-grasping jaws slid'ablealong the guide member; a pair of locking detents disposed onoppositesides of the guide member and having inner ends movable into theinterior oithe guide member to arrest forward movement of the jaws afterthe latter have been moved into a position rearwardly of the detents;yielding means urging the detents inwardly of the guide member; aswingably mounted cam plate having slots therein inclined: relative totrue arcs of a circle described aboutthe pivotal point ofthe-plate;studs secured to the detents eX--- tending into the slots of the camplate; the slots being inclined and cooperating with the studs to movethe detents apart when the canr plate is swung in one direction againstthe ac-' tion of said yielding means; at least one of the slots having anotch therein to receive the stud associated therewith whenthe earnplate has been swung to move the detents apart.

4. In combination; a. guide member extending longitudinally of asemi-trailer; a pair of co opera ting king-pin-grasping jaws slidablealong the guide member; a: pair of lOGkiIlg' detents dis-- posed onopposite sides of the guide member and having inner ends movableintotheinterior of the guidemember to arrest forwardmovement; ofi thejawsafter the-latter have'been moved. into: a position rearwardly of thedetents; yielding; means urging the detentsiinwardly' oi'i the guidemember; a s-Wingably mounted cam plate having slots therein inclinedrelative to true arcs of; a circle described about the pivotal pointof:the plate; studs secured to the detents and extending into the slots of.the cam plate; the slots being inclined and cooperating with the studsto move the detents apart when the cam plate is swung in one directionagainst the action of said yielding means;. at least one of the slotshaving a notch therein to receive the stud associated therewith when thecam plate has been swung to move the detents apart; the detentassociated with the notched slot having a tapered inner. end engageablewith one of the jaws for retracting that jaw further from in front ofsaid jaw after said detent has been partially withdrawn; the taper ofsaid inner end of that detent being dimensioned to; free said stud fromthe notch when said jaw slides thereover.

5. In combination: a guide member extending longitudinally of asemi-trailer and having an outwardly-flaring throat at its forward end;the guide. member having a king-pin receiving extending slat extendingrearwardly thereof from its throat; a. cam-operating? reach-barreciprocably disposed in; the guide member; a pair of co-. actingclamjaws hinged to the forward end of; the reach-bar: the. jaws, whendisposed in the t'lsiroat,v being swingable away from one another' forpassage of a king-pin therebetween, withthe king-pin movable along theslot; and a locking dog pivotally' secured to one of the jaws: andhauling an end: swingable: into engagement with a stop on the guidemember when the jaws are disposed in the throat to' retain. thereach-bar against rearward movement; thedog having a portion disposed inthe path of and movabl'e bythe king pin when the latter is movedrearward] along: the slot for swinging the dog out of. engagement withthe stop.

61. In combination: a guide member extending longitudinally of asemi-trailer and having an outwardly-flaring throat at its forward end;the guide member having a king-pin receiving eX- tending slot extendingrearwardly thereof from its hroat; a cam-operating reach-barreciprocably disposed in the guide member a pair of co aoting clamjawshinged to theiorw'a'rd endof the reaelnb'ar; the jaws-,when disposed inthe throat, being: swingable away from one another for passage of:airing-pin therebetween, with the king-pin movwle along the slot; 9;locking dog pivotally'secured-to; oneof the jaws and-having anendswingable: into engagement with a stop on the guide member. when the:jaws are disposed in the.- throat to retain. the. reach-bar againstrearward movement;v therdogi havinga portion disposed in the path of andmovable by the king-pin when the latter is moved rearwardly' along theslot for swinging the. dog out ofv engagement with the stop; andatension spring working between: one ofv the jaws: and the dog. andurging. the latter into engagement with the stop:

71 In combination: a reach-bar; a pair of coacting. clam jaws, hinged tothe reach-bar, and arranged; to: swing toward and away from each other;and alocking. dog pivotallysecured to one of the jaws at a pointlaterally of. the hinge connection; between. the jaws; the dog having ahookeshaped end forv embracing the head of: a kingrpindisposed to oneside of the pivot of the dog; the. dog having. a. lever-like portion at.its other end..

8.. In combination: a reach-bar; a pair of onacting, clam. jaws hingedto the reach-bar, and arranged to swing, toward. and away from eachother; a locking dog pivot'ally secured to one of the jaws at a point.laterally of the hinge connection between the jaws; the dog having ahook-shaped end for embracing the head of a king-pin disposed to oneside of the pivot of'the. dog;. the dog having a lever-like portion atits other end; and a tension spring working between the other jaw andthe lever-like portion to pull them toward; one another.

RALPH WAYNE STARR.

0 Number Name Date 1,921 250' Connors: etal Aug. 8, 1933 2;120;509-Reidi June 14, 1938 2,246310- Wilson June: 17, 19451

